IF your son planning on applying for a ROTC scholarship, everything should be done before December 1st. So he needs to be working now on this process. The medical exam can be the most time consuming, AF and Navy do not give the exam until your are offered a scholarship.
Because the first AFROTC board meets early December you need to have everything done 2 week before this board. I am sure that the other services have early boards too. The more boards you meet the more chances for your file to be reviewed.
I had both my children have all the college applications done by Sept 1st. It really gave the kids a stress free senior year. They both were accepted to colleges in Sept this made them look at their friends freaking out in December about the deadlines and thank me for pushing them to do this so early. This also made the kids' GC happy, she was able to write letters when she had time, not when 20 others want them by next week too.
One thing that most GC don't tell you/know that the earlier you apply it makes you look very interested in their school. When a school starts handing out merit aid, they look at the first admits. Just ask the schools they will tell when their aid pot runs dry.....
My D received 2 full tuition scholarships and 2-3/4 tuition scholarships. She graduated debt free and it cost us about 15K for her 4 years. My S was offered 2 free rides at private schools, with his ROTC scholarship. Plus 3 other schools offered him flat out merit aid. He picked a school that if he lost the scholarship he could still pay for out of his college fund. (Things happen injury, illness and Military cut backs)
I would feel that you are already running late, schedule his interviews with the ROTC units now.